1. Field of the Invention
The present invention relates to a housing for an electronic circuit for a fuel pump, composed of a printed circuit board, electric and/or electronic components arranged on the printed circuit board, a base and a cover which is connected to the base, wherein the base and the cover form the housing.
2. Description of the Related Art
An electronic circuit is used in fuel pumps of motor vehicles in order to feed fuel from a fuel container to an internal combustion engine. The electronic circuit is required to operate the electronically regulated electric motor of the fuel pump. The printed circuit boards which are used here are generally composed of fiber-reinforced plastic. The plastics used are epoxides or else duroplasts and thermoplasts or specific plastics such as PTFE. The fiber materials used are glass fibers, plastic fibers and carbon fibers as well as plant fibers and paper. Owing to the arrangement of the electronic circuit in the fuel pump or in the immediate surroundings thereof, the electronic components and conductor tracks have to be protected against the aggressive components of the fuel. Since fuel components also diffuse through printed circuit boards, they do not offer sufficient protection. For this reason, in order to protect the electronic circuit the printed circuit board is arranged with the components inside a sealed metal housing. The feedthroughs for the electric connections have to be embodied as glass/metal feedthroughs. The disadvantage of these glass/metal feedthroughs is the complexity and the cost involved in manufacturing the seal.
It is also known to arrange components on a ceramic base and to solder the ceramic base to and metal cover, with the result that the components are arranged protected between the ceramic base and the cover. The ceramic base acts here as a diffusion barrier for the fuel.
A disadvantage in known embodiments is the considerable cost factor of such housings, which cost factor permits economic use only for high-value applications.